Furnace door



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h[ -IIE -][v Fl-ifI "I Mx @ik TU# .w @ik FURNAGE DOOR Filed narqm 1944 Patented Aug. 26, 1947 UNITED srA'rEs PATENT f OFFICE .URS$1.015 l v Arthur som, chicago, n1. f Application March '1, 1944, serial No. 525,469

2 Glailms. (Cl. 11o-173) The objects and advantages of the invention will be fully apparent from the-following specitlcation and appended claims when read in connection with the accompanying drawings, in which: Figure 1 is an inside face view of an open hearth furnace door embodying the present invention.

Figure 2 is a vertical section on line II-II of Figure 1.

Figure 3 is a fragmentary sectional perspective view illustrating the manner of tack welding 'metal-clad refractory bricks to the body of the furnace door. 'The majorityof basicopen hearth furnace doors as constructed prior to my invention frequently consist of a steel water-cooled frame which encloses one fiat lface and the four edges of a. panel of fire-clay. Because of the open hearth temperatures, which range from approxitangular prism. and is clad on four sides with lmately 2700 F. to 2900 F., the fluxing action of lime and iron oxide in the furnaceatmosphere, and the mechanical and thermal shocks to which door linings are subjected, their lives are very short, and replacements have frequently been required for eachdoor after approximately every fifteenl heats, which in normal operation e means approximately every week. Since the average open hearth furnace has five doors, it is evident that' in a steel mill containing several furnaces, an inordinate amount of maintenance n time and labor must be devoted to changing and relining lthe doors.

In recent years various attempts have been i made lto improve the useful lives of open hearth door linings. Chief among these has been the development of stud-type doors', which -have materially increased door life. In construction, however, such stud-type doors consist of basic monolithic refractories of chrome ore, magnesite, olivine orvvarious combinations of these, rammed into the water-cooled recesses of the door frame into which steel studs or bolts have been secured. These studs serve both to anchor the refractory in place and to provide for a rapid heat transfer to the cooling water, thus cooling the refractory face and prolonging the 'life of the door. However, the installation cost of a stud-type door is several times that yoi? a brick-lined door. The primary disadvantage of the stud-type door lies in the time andlabor required in the preparation and installation of vthe ramming mixture and the removal and replacement of the 'studs after use.

2 y The present' invention aims to overcome the shortcomings of the priorfpractices above referred to, and at the same time to provide a door which will have increased service life.

Referring particularly to the drawings, my improved door comprises a hollow body such as indicated at I0, so as to provide a water chamber I2 which is suitably connected with an inlet pipe Il and an outlet pipe I8 to permit circulation of a coolant such as water in a manner well known to those skilled in the art. Lugs l1 are adapted to connect with any conventional form of door support. 'I'he body of the door is provided with a recessed portion I8 adapted to accommodate a multiplicity of refractory bricks 20. Each of these bricks is substantially in the form of a recsheet metal. For example, each brick may be surrounded with a metallic sleeve 22. The inner each brick is thus individually anchored to the door body, and cannot become loosened and fall` v,

out as the `result of shrinkage or mechanical abuse. When the metal-clad bricks are initially installed in the cavity i8' of the door, there will be a slight clearance space between adjacent,v

bricks which may range from inch to 'ts inch in practice. When the door is put into use, expansion eectively seals the spaces between the bricks. By the use of metal-clad basic brick constructed and arranged in the manner herein shown and described, it is possible to obtain an essentially basic lining of greater density and greatererosion-resistance than is obtainable with l' the rammed door linings heretofore available, and at the same time provide positive assurance against the type of door failure common to both fire-clay and basic brick linings laid up in the conventional manner.

The brick-lined door illustrated constructed from 9" x i1/2" x 3" metal-encased basic brick in which the metal encloses the four larger faces while no metal is present on the two ends. In order to utilize'all of the metal, in which instance one edge of the metal casing of each brick must touch the water-cooled door and the opposite edge terminate in the inner surface of the door, I cut each 9-inch brick in half, thus obtaining two metal-clad bricks each 41/2 inches long. The bricks are then placed in the door cavity I8, with one of the exposed faces turned outwardly and the other abutting against the wall I8* of' the door cavity. Then the two.edges is preferably of the metal casing are tack-welded to the door frame at a plurality of points 24 around the perimeter of the casing in the region of the intersection of the casing 'with the wall I8a of the cavity. The work of installing these metal-clad brick should generally progress from the four outer corners of the door cavity toward the door tile '26 which has a peek-hole 28 therein registering with the usual peek-hole formed in the doorv body. Inthis way 4all of the brick arereadily accessible for tack-welding to the doorfnody in a manner which will be readily apparent to those skilled in the art.

Various modications may be made without departure from the invention as defined, in ther appended claims.

I claim: A I 1. A Lmetal furnace door comprising a body porbeing formed with a recessed portion, a protective lining substantially filling said recessed portion comprising a multiplicity ofv separately preformed refractory bricks, each surrounded on four faces by a unitary sheet metal sleeve which at the edges at one end thereof is secured to said door body within the said recessed portion by a series of spaced bodies of tack welded metal to thus individually anchor each metal encased brick to the door body, the construction andarrangement thus being such that there are tw`o thicknesses of sheet sleeve metal between all adjacent bricks, the metal sleeve surrounding each brick being in contact with the metal sleeves of the tion having a face whichisadapted to be disposed overa furnace door opening, a multiplicity of separately preformed 'refractory bricks disposed upon and covering said face, each surrounded on four faces by an individual unitary' sheet metal sleeve having the edges at one end `thereof tack welded to said face of the body ofthe door by a .series of spaced welded joints of restricted areas to individually anchor the inner edges of the sleeve to the door, the arrangement being such that there are two thicknesses of sheet sleeve metal between al1 adjacent bricks, themetal sleeve surrounding each brick being in Contact with the metal sleeves of the bricks adjacent thereto.

2. A furnace door of the character described, comprising a hollow metallic door body adapted to have a coolant circulated therethrough and formedvvithy a face which is adapted tobe disposed over a'furnace door opening, said face bricks adjacent thereto.

ARTHUR SONTZ.

REFERENCES CITED The-(following references are of record in the file of this patent:

UNITED s'rivrEsr` PATIENTS Heuer Apr.- 18, -1939 

